Free Cisco 350-501 Practice Exam with Questions & Answers | Set: 10

The correct configuration for MPLS LDP synchronization with OSPF process 1 on router R1 is to use the command mpls ldp igp sync holddown 60 under the OSPF process configuration. This ensures that the MPLS LDP synchronization is enabled and held for 60 seconds with OSPF process 1, which helps prevent black holes in MPLS networks during the convergence process by ensuring that routes are not advertised until LDP is fully operational and labels have been exchanged between adjacent routers.

References:

• Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) - Cisco SPCOR
• Additional resources on Cisco’s Service Provider training: Cisco Service Provider Training

When router A is the Rendezvous Point (RP), Protocol Independent Multicast - Sparse Mode (PIM-SM) is the appropriate mode to configure. In PIM-SM, multicast traffic is initially sent to the RP by the sources. The receivers express their interest in receiving specific multicast traffic by sending join messages towards the RP. This mode is efficient for networks with sparse multicast groups where not all members participate in every multicast session. References: = Implementing and Operating Cisco Service Provider Network Core Technologies course materials.

 To prevent packets from being forwarded beyond the service provider domain when the Label Switched Path (LSP) is down, the engineer must configure a private IP address as the destination address of the headend router of Cisco MPLS Traffic Engineering (TE). This ensures that if the LSP fails, the packets will not be routable over the public internet, thus containing them within the service provider’s network.

References := Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) documentation provides guidelines on MPLS TE configuration, including the use of private IP addresses for headend routers to maintain traffic within the service provider domain. This practice is aligned with the principles of traffic engineering and network containment for service providers.

 Implementing CSC VPN services for a new backbone carrier provides several benefits. Firstly, it maintains a single backbone network, which simplifies the VPN implementation to customers (A). This eliminates the need for each Level 2 carrier to create and maintain a separate backbone network, thus lowering maintenance costs and simplifying management operations. Secondly, it supports a scalable growth strategy that services multiple customers efficiently (D). The Level 1 carrier can use one backbone network to provide VPN and Internet services for multiple Level 2 carriers, increasing revenues and efficiency.

References: The benefits of implementing CSC VPN services are detailed in the Huawei IP Encyclopedia, which explains the Carrier’s Carrier (CSC) networking solution in BGP/MPLS IP VPN2.

 Cisco MPLS Traffic Engineering (TE) tunnels necessitate a link-state routing protocol like OSPF or IS-IS because these protocols use Shortest Path First (SPF) calculations. The tunnel endpoints leverage these SPF calculations to implement the tunnel, ensuring an efficient and optimized path through the network. This is essential for MPLS TE, which aims to optimize network resource utilization and improve traffic distribution across the network.

References: Cisco Community, Cisco Documentation

• Option A corresponds to the desired configuration. It uses an access-list to permit IGMP joins for the specific multicast group 239.10.10.10 from the source 172.20.20.3.
• Options B, C, and D do not match the desired configuration. They either allow all IGMP traffic or do not specify the correct source and group addresses.

References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) source book

Path Computation Element (Calculates paths through the network, keeps TE topology database information, sends path status updates)

Path computation Client (sends path calculation request, sends path creation request)

Path Computation Element (PCE)

Represents a software module (which can be a component or application) that enables the router to compute paths applying a set of constraints between any pair of nodes within the router’s TE topology database. PCEs are discovered through IGP.

Path Computation Client (PCC)

Represents a software module running on a router that is capable of sending and receiving path computation requests and responses to and from PCEs. The PCC is typically an LSR (Label Switching Router).

https://www.cisco.com/c/en/us/td/docs/routers/crs/softwa re/crs_r5-3/mpls/configuration/guide/b-mpls-cg53x-crs/b-mpls-cg53x-crs_chapter_0110.html#con_1279822

Using verbose knob in above command will list all the hops as below: R1#traceroute mpls multipath ipv4 10.1.5.5 255.255.255.255 verbose https://www.cisco.com/c/en/us/support/docs/multiprotocol-label-switching-mpls/multiprotocol-label-switching-mpls/200097-MPLS-LSP-Multipath-Trace.html